docs: add fallback npm install:ci instructions to README

Add instructions to use 'npm run install:ci' as a fallback option if 'npm run install:all' fails. This addresses the dependency issue where npm-run-all needs to be installed before running the install:all script, providing clearer guidance for developers setting up the project locally.

Signed-off-by: Eric Wheeler <[email protected]>

README.md

@@ -119,6 +119,12 @@ Make Roo Code work your way with:
     ```bash
     npm run install:all
     ```
+
+if that fails, try:
+    ```bash
+    npm run install:ci
+    ```
+
 3. **Build** the extension:
     ```bash
     npm run build